Infection control bedding product

ABSTRACT

An infection control bedding product such as a pillow, duvet, mattress, cushion or such like having a sealed cover and having a deformable filling material, may comprise a liquid impermeable air permeable microbial barrier vent. The vent includes an oleophobic expanded polytetrafluoroethylene (PTFE) membrane extending past the perimeter of the aperture and a nonwoven layer extending past the perimeter of the aperture. A gasket may be bonded to the PTFE membrane, the nonwoven layer and the cover to form a liquid impermeable seal rendering the infection control bedding product liquid impermeable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/678,124, now U.S. Pat. No. 8,651,233, issued Oct. 22, 2013, which isa National Stage filing of International Application Serial No.PCT/EP2008/062265, filed Sep. 15, 2008, which claims the benefit ofIrish Application Serial No. S2007-0653, filed Sep. 13, 2007. Thedisclosures of the foregoing patent and applications are expresslyincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention concerns improvements in and relating to ahermetically sealed infection control bedding product such as a pillow,duvet, mattress, cushion and such like. The present invention alsorelates to a method of manufacture of a vented hermetically sealedinfection control bedding product.

BACKGROUND TO THE INVENTION

Infection control and cross infection present a major problem forhospitals today, leading to considerable expense and inconvenience.Bacterial strains have developed which are increasingly more resistantto treatment by antibiotics. Therefore, once an infection is establishedin a hospital, it is often difficult to eradicate and can spread quiterapidly. A problem known as “strikethrough”, where a contaminated fluidpenetrates to an interior of a infection control bedding product such asa pillow, duvet, mattress, or cushion, is well known. If “strikethrough”occurs, then there is a considerable risk of cross infection associatedwith any of these infection control bedding products since they arelikely to be used subsequently by many different patients. Indeed, thisproblem arises in any situation where there is a regular change inpersons using pillows, duvets and the like, such as, for example, inhotels and guesthouses. Furthermore, in the home, many people withallergies and breathing disorders have problems with fungal infectionand dust mites.

There are numerous commercially available materials typically used forwaterproof covers on mattresses, typically comprising a knitted or wovennylon fabric, with a thermoplastic coating, typically polyurethane,applied. The knitted or woven fabric provides mechanical strength, whilethe thermoplastic (polyurethane) coating provides waterproofing.

Some such fabrics are termed “vapour permeable” because tiny pores existat sub-micron level in the coating, that nominally allow transport ofwater vapour molecules. However, these fabrics do not allow transfer ofair at sufficient rates to ventilate a pillow.

U.S. Pat. No. 4,637,377 discloses a surgical pillow for supporting theheart or other body organs of a patient during surgical procedures. Thesurgical pillow disclosed in U.S. Pat. No. 4,637,377 has a foam filledcasing with a vent in the casing to permit release of entrapped airwithin the casing upon compression of the pillow during use.

U.S. Pat. No. 5,038,431 discloses a pillow for dispensing medication.The pillow has an outer sheet forming a pocket for reception of fillingmaterial. The pocket has a vent opening and the filling material isimpregnated with a medicament. When the vent is open, a person isexposed to medicament vapour which escapes through the vent opening.

These prior art pillows do not address the problem of “strikethrough”.

U.S. Pat. No. 4,445,241 discloses an air tight and fluid tight cover forpadded bodies, mattresses and the like. The cover has a top, a bottomand a plurality of side parts. At least one opening provides ventilationbetween the interior of the cover and the ambient atmosphere. At leasttwo of the side parts are formed by at least an interior, middle andexterior layer of material. Air passage openings offset with respect toeach other are provided in the interior and middle layers of material.At least one filter is disposed between the middle and outer layer ofmaterial. A plurality of connecting seams extend partially transverselyacross the width of the side part from diametrically opposite points ofthe upper and lower longitudinal edges of the side parts toward alongitudinal center line bisecting the side part. The connecting seamsdefine a plurality of pockets in which the filters are disposed. Theconnecting seams also define air passages between the individual layersof material for trapping coarse granular particles therein.

U.S. Pat. No. 4,445,241 discloses a moisture and air-tight cover for apillow in which welded seams are provided to constitute pockets forreception of filters for particles and bacteria. This is a complexproduct which is difficult and expensive to produce. The seams define aserpentine air passage between the interior and exterior of the pillowand each air stream contains at least two filters. However, thesefilters are not, and cannot be, physically connected to one another bywelding or otherwise, as in the present invention, and in fact at leastone filter at the outer opening of the air passage can be removedthrough slit-shaped openings 28 (see column 4, lines 13 to 15). Theserpentine passage actually provides a breeding ground for bacteria thusdefeating the purpose.

A further distinction and advantage of the present invention as comparedto U.S. Pat. No. 4,445,241 is that the filter cannot be removed from thepillow deliberately or inadvertently, thereby possibly compromising thefiltration, as is possible with the design of U.S. Pat. No. 4,445,241.

A major problem to overcome when developing a sealed pillow is to ensureadequate ventilation of the pillow core. A pillow may be made airtightby using an occlusive medium for the cover, and welding the seams.However, the lack of ventilation in such a pillow creates problems inuse, such as the following problems:

-   -   1) When the head rests on the pillow, the pillow does not        deflate. This is uncomfortable, and creates an unstable surface        for the head to rest on.    -   2) Impact to the pillow, either accidentally or when the head        first makes contact, creates a great deal of stress on the        seams, which may burst as a result.    -   3) Gradual ingress of water vapour particles by diffusion        creates condensation within the pillow, leading to accelerated        degradation of the materials within.

Furthermore, many attempts have been made to provide pillows, cushionsor mattresses that have a barrier for contaminant particles or liquid,but none has been entirely successful. The best effort to date andcurrently in use in the healthcare sector, is the pillow disclosed inthe Applicants' patent specification no. EP 1 222 886. Nevertheless, theinfection control bedding product of the present invention providessignificant advantages over the pillow disclosed in EP 1 222 886.

European Patent Specification No. EP 1 222 886 discloses a pillowcomprising a sealed outer liquid impermeable cover, filling materialretained within the outer cover, a vent in the cover communicatingbetween an interior and an exterior of the cover and a bacteriologicalair filter means mounted across the vent to provide for filtering of airpassing through the vent, wherein the filter comprises an outer layer ofliquid-resistant material with a number of superimposed inner filtermaterial layers attached to the outer layer, and wherein the materiallayers are welded together and to the cover across the vent. Provisionof a bacteriological filter prevents the ingress of bacteria to aninterior of the cover.

The outer layer of the filter of the pillow disclosed in EP 1 222 886does not provide adequate liquid resistance. Even if a filter mediumconstructed using the same materials as the outer layer of the EP 1 222886 filter could be made to be fully liquid resistant, such a filtermedium would not provide adequate ventilation for the product tobreathe, resulting in ballooning of the pillow in use. This wouldprovide an uncomfortable surface for a user to rest on, and could burstfrom internal pressure when in use. In addition, the method of weldingeach of the five layers of the filter of EP 1 222 886 is time consumingand inhibits the viability of the product from a mass production andcommercial point of view.

For example, EP 1 222 886 only teaches a liquid resistant as opposed toa liquid proof outer layer to the filter. The textile disclosed in EP 1222 886 is a nylon material which will admit liquid at relatively lowlevels of pressure (i.e. relative to the membrane of the presentinvention). If the textile disclosed in EP 1 222 886 was made liquidproof, it would require that the pore size would be reduced to such anextent that such pore size would prevent the pillow from “breathing” ordeforming, or inhaling/exhaling to the required level.

The present invention addresses and solves these technical problems. Aswill be further described in detail hereinbelow, the filter membraneincluded in the present invention is more like a strengthened skin thatbreathes through osmosis. This is in contrast to the filter of EP 1 222886 which must be more coarse in order to form part of the product andis only liquid resistant rather than liquid proof. The pillow of EP 1222 886 has a woven synthetic outer textile backed by non-wovenpolyester layers. The membrane of the present invention is fundamentallydifferent from the medium disclosed in EP 1 222 886.

The filter membrane in accordance with the present invention overcomes anumber of technical problems. The filter membrane included in thepresent invention, being like a thin skin, must be strengthened so thatthe infection control product of the present invention would be fit foruse in the environment in which it would be used and so that it couldwithstand the challenges that are likely to be present in use. Thisneeded to be achieved without compromising key properties of the filtermedium and the pillow including filtration of contaminants and“breathability” of the pillow.

EP 1 222 886 discloses the welding together of five or six layers ofmaterial. If, as is taught in EP 1 222 886, each layer is welded to theother and then to the liquid resistant outer fabric and then the wholemedium is welded across the aperture in the pillow, then the processbecomes non-viable from a manufacturing and mass production point ofview. If they are all welded together in one action, then the sealintegrity and consequently, the pillow is compromised as the strengthand integrity of the seal between each individual layer is compromised.Further, the drawings and description of EP 1 222 886 illustrate thatthe filter medium should run diagonally and be welded at one end intothe top seam of the pillow and at the other end into the side seam ofthe pillow. This means that a further thick 2 thick layer of PU-coatedfabric need to be welded through, in addition to the 5/6 layers of themedium, thereby giving rise to further manufacturing challenges andquality/integrity issues. In other words, EP 1 222 886 does not teach aproduct that when mass-produced can provide the benefits of the presentinvention.

A further problem that emerged with the pillow disclosed in EP 1 222 886was that the filter medium itself as well as the seal between the filtermedium and the pillow cover could burst or tear if pressure equivalentto a patient leaning on their elbow, was applied directly on the filtermedium itself. Therefore, a further problem overcome by the presentinvention is the provision of a new and vastly improved filter mediumthat could withstand pressure of this nature whilst providing efficientbacteriological properties.

The filter medium disclosed in EP 1 222 886 is described as efficient toblock the passage of particles having a size of 0.6 microns or greaterwhereas the present invention including a new medical membrane designwhich has been proven to be efficient to block the passage of particleshaving a size of 0.2 microns or greater. Therefore the present inventionaddresses a greater number and wider category of possible contaminants.

Accordingly, the present invention relates to an improved infectioncontrol bedding product, e.g. a pillow, having technical improvements inparticular, superior liquid resistance over the pillow disclosed in EP 1222 886.

SUMMARY OF THE INVENTION

Embodiments of an infection control bedding product are disclosedherein. In some embodiments, the infection control bedding productincludes a filling material and a cover enclosing the filling material.The cover includes an aperture configured to vent the infection controlbedding product. The infection control bedding product also includes afilter membrane; a strengthening layer attached to the filter membrane;and a gasket attached to the strengthening layer. The gasket extendspast the perimeter of the aperture and is attached to the cover. Theinfection control product is substantially liquid impermeable, airpermeable and a microbial barrier.

In some embodiments, the infection control bedding product includes afilling material and a cover enclosing the filling material. The coverincludes an aperture configured to vent the infection control beddingproduct and and a liquid impermeable polyurethane coating. The infectioncontrol bedding product also includes a substantially liquid impermeableair permeable microbial barrier filter membrane; a strengthening layerattached to the filter membrane and extending past the perimeter of theaperture. The strengthening layer is bonded to the internal surface ofthe cover. The infection control product is a liquid impermeable airpermeable microbial barrier.

In some embodiments, the infection control bedding product includes afilling material; a cover enclosing the filling material and having anaperture. The cover includes a liquid impermeable material. Theinfection control bedding product also includes a liquid impermeable airpermeable microbial barrier vent including an expandedpolytetrafluoroethylene (PTFE) membrane extending past the perimeter ofthe aperture; and a nonwoven layer extending past the perimeter of theaperture. A gasket is bonded to the PTFE membrane, the nonwoven layerand the cover to form a liquid impermeable seal rendering the infectioncontrol bedding product liquid impermeable.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described more particularly with reference tothe accompanying drawings, in which are shown, by way of example only,two embodiments of a pillow in accordance with the present invention.

The embodiments shown in the drawings comprise an infection controlpillow but of course, it is to be understood that many other infectioncontrol bedding products could be manufactured in accordance with thepresent invention.

In the drawings:

FIG. 1 is a perspective view of the outside of a first embodiment of apillow in accordance with the invention;

FIG. 2 is a perspective view of the outside of a pillow in a secondembodiment;

FIG. 3 is a plan view of the inside of a pillow in the secondembodiment;

FIG. 4 is an exploded view of the layers of materials included in athird and most preferred embodiment of the infection control beddingproduct of the present invention;

FIG. 5 is a close up of the exploded view of the infection controlbedding product in the third embodiment, shown in FIG. 4;

FIG. 6 is a perspective view of the third embodiment of the infectioncontrol bedding product of FIGS. 4 and 5, with the layers now shownassembled on the infection control pillow product;

FIG. 7 is an exploded cross sectional view of the assembled layersincluding the pillow cover, PU gasket, spun-bonded polypropylenestrengthening layer and the medical membrane stacked on top of eachother, in situ, before welding. (After welding, the layers will becompressed together);

FIG. 8 is a perspective view showing the assembled layers stacked on topof the welding tool with the welding tool surface being dimensioned sothat it has a greater surface area than the area of the assembled layersso as to ensure that the respective edges are completely sealedtogether; and

FIG. 9 is a plan view showing the final infection control product withthe pillow cover welded to the filter medium and the strengtheninglayer.

According to the present invention, there is provided a hermeticallysealed infection control bedding product such as a pillow, duvet,mattress, cushion or such like having a sealed cover and having aresiliently deformable filling material, comprising: a vent means in thecover, characterised in that the vent means comprises a filter mediumincluding a filter membrane for the removal of particles of microbialsize and wherein the filter medium also comprises a strengthening layerof material for providing mechanical strength to the filter medium,whereby the filter medium allows air flow therethrough but issubstantially impermeable to liquid while maintaining a barrier toparticles of microbial size.

Thus the infection control product of the present invention has theadvantage that the vent allows air to pass through so as to provideventilation for the pillow while preventing liquid including watermoisture, water droplets, human sweat, sputum, urine from passingthrough the vent.

Accordingly, the problems associated with the prior art are overcome byincorporating into the cover of the pillow, a vent comprising a filtermedium which allows substantial air flow, but is substantiallyimpermeable to liquid and maintains a barrier to particles of microbialsize.

Conveniently, an aperture is formed in the cover of the product and isadapted to receive the vent.

Ideally, the aperture in the cover of the infection control product islocated so that the seam of the filter medium and aperture is notintegral with any perimeter seam of the cover of the infection controlproduct.

Preferably, the layer of strengthening material comprises a materialproviding mechanical strength, and advantageously may comprise a spunnon-woven synthetic material such as polypropylene (PP).

Preferably, the filter medium includes a means for substantiallypreventing fluid ingress, while allowing air to permeate. Conveniently,the liquid resistance may be achieved by virtue of the filter membranebeing manufactured of a hydrophobic material or oleophobic material.

Advantageously, the filter membrane comprises a thermoplastic non-wovenmaterial which may include polytetraflouroethylene (PTFE).

In the preferred embodiment, the filter membrane is manufactured of anoleophobic expanded polytetrafluoroethylene (PTFE) material. Ideally,the filter membrane is manufactured of an oleophobic PTFE membrane andalso includes a non-woven polyvinyl chloride (PVC) membrane support.

The filter membrane functions as a bacteriological filter. This has theadvantage that it prevents the ingress of bacteria to an interior of thecover.

Advantageously, the filter membrane is adapted to block passage ofparticles having a size of 0.2 microns or greater.

Preferably, the pore size of the filter membrane is between 0.2 micronsand 4 microns, and is preferably between 0.5 microns and 4 microns, andmay be between 1 and 4 microns. Advantageously, the pore size of thefilter membrane may be a size between 2 and 4 microns.

Given the low micron size of the pore size of the filter membrane, thereis a risk that if the filter medium of the present invention wasincorporated in a pillow in the same way as described in EP 1 222 886that the internal pressure when a patient exerts a force onto the pillowwould cause the pillow to tear. It should be noted that the same riskapplies to the majority of the uses to which the filter medium is suitede.g. wheelchair cushion, mattress and so on.

Accordingly, in the preferred embodiment, the filter medium comprisingthe filter membrane and strengthening material are bonded together andto the cover of the infection control product, at an aperture in thecover of the infection control bedding product such as a cushion,pillow, duvet, mattress or such like so as to provide a vent in theinfection control bedding product. The bonding of the layers together ispreferably achieved by welding. In the most preferred embodiment, thevent includes a gasket (PU) and the gasket is also bonded with thefilter medium to the cover of the infection control product so as toachieve a sealed vent.

Advantageously, the cover of the infection control bedding product suchas a pillow is manufactured of polyurethane coated polymeric material,for example polyurethane coated nylon.

Most preferably, the infection control product of the present inventionincludes a gasket which is ideally of dimensions corresponding to thedimensions of the aperture in the cover of the infection control productinto which the vent will be located and subsequently bonded to the coverof the infection control product.

Conveniently, the gasket is manufactured of the same material as thecover of the infection control product. Advantageously, the gasket ismanufactured of a thermoplastics material such as polyurethane (PU). Theinclusion of the gasket in the vent of the infection control productensures that the edges of the assembled vent comprising the filtermembrane/strengthening layer and gasket bonded to the cover fabric ofthe bedding product (such as a pillow cover) are sealed and impermeableto liquid.

After the components of the vent have been located in the aperture inthe cover of the product, all of the components of the vent togetherwith the cover of the infection control product itself are bondedtogether in a manner that provides a seal which is impermeable toliquid.

The present invention also provides a method of manufacture of thehermetically sealed infection bedding product comprising the steps of

-   -   a) providing a filter membrane    -   b) providing a strengthening layer    -   c) providing a cover of the bedding product, the cover having an        aperture adapted to receive the filter membrane and        strengthening layer; and    -   d) affixing the layers a), b) and c) together so that the layers        are affixed together to form a seal which is impermeable to        liquid.

Ideally, between steps (b) and (c), a gasket is provided and the gasketis also affixed with the filter membrane and the strengthening layer tothe cover of the product.

Conveniently, the step of affixing the layers together may be achievedby bonding such as by glueing or welding as the layers must be affixedtogether so as to form a seal which is impermeable to liquid.

Referring now to FIG. 1, a first embodiment of a pillow in accordancewith the invention is indicated generally by reference numeral 10. Thepillow 10 comprises a waterproof coated fabric cover 1 and incorporatesa section of filter medium 2. The pillow is, preferably, ultrasonicallywelded at seams 3. The fabric cover 1 encases the filling of the pillowand is formed of a weldable material which is coated in polyurethanewhich provides a fluid resistant (waterproof) coating on the cover.

The filter medium comprises a filter membrane which may comprise anon-woven membrane, made of thermoplastic material. In the preferredembodiment, the filter membrane is manufactured of an oleophobicexpanded PTFE membrane having a membrane support backing comprised of anon-woven polyvinyl chloride (PVC). The PVC backing layer is fused orlaminated to the PTFE filter membrane. It has been found byexperimentation that the optimal pore size of the filter membrane forthis use is in the range of 2-4 microns. This pore size allowssufficient air-flow to ventilate the pillow dynamically when impacted bya user's head. Air flow through the pillow of the invention, has beenmeasured and found to be in the region of 20-40 Litres per minute persquare centimeter at 1 bar differential pressure. This pore size hasalso proved by experimentation to have 100% filtration efficiency interms of removing microbial load, while providing resistance to water inthe region of 0.2-0.8 bar entry pressure.

The intrinsic mechanical weakness of the necessarily thin PTFE/PVCfilter membrane is overcome by providing an additional strengtheninglayer of a synthetic material such as polypropylene, preferably spunfibre polypropylene, which provides mechanical strength to the filtermembrane. This assembly is referred to as the “filter medium”, indicatedgenerally by reference numeral 2 in FIG. 1.

Referring now to FIGS. 2 and 3, a preferred arrangement for welding thevarious components together will be described. In the drawings, likenumerals refer to like features of the pillow in the first and secondembodiments.

In the first embodiment of the pillow 10, the filter medium 2 spans theentire corner of the pillow 10 and so the filter medium 2 isincorporated into the welded seam. However, it was found byexperimentation that if a pillow bursts in use, the most common point offailure was the welding seam, at that point where the filter medium 2 isincorporated into the seam. This mechanical failure was thought to behappening for two reasons:

-   -   1) The geometry of the seams renders them subject to peel        forces; and    -   2) The weld strength when welding the filter medium 2 to another        substrate is substantially stronger when the expanded        polytetrafluoroethylene (PTFE) (strength-providing) layer is        next to the substrate to which the material is being welded. On        the other hand, if the waterproof layer (i.e. non-woven PVC) is        next to the substrate to which the filter medium is being        welded, delamination of this waterproof layer may occur, and a        strong weld is not achieved.

The geometry of the first embodiment of the pillow 10 in which thefilter medium is incorporated into the seam dictates that, for thewaterproof PVC layer to be facing outwards which is necessary to avoidwetting of the expanded polytetrafluoroethylene (PTFE) layer), thewaterproof PVC layer had to comprise the welded face of the filtermedium. This arrangement gave rise to a weaker weld than was desired.

Accordingly, a second embodiment is provided and a pillow in this secondembodiment of the invention is shown in FIGS. 2 and 3. The pillow inthis second, preferred embodiment, is indicated generally by referencenumeral 20 and comprises a waterproof pillow cover 21, a filter medium22, and seam 23. The cover 21 is manufactured of polyurethane-coatednylon. Referring to FIG. 3, in the second embodiment, the pillow 20includes a window 24 which is die-cut in the cover material 21. Thiswindow 24 may be any shape, and is substantially removed from the seams23 of the pillow. FIG. 3 shows the inside of the pillow cover 21.

As shown in FIG. 3, the filter medium 22 is cut so that it is a similarshape and of similar dimensions to those of the window (aperture) 24except that the filter medium 22 is slightly larger than the window 24to allow overlap of the filter medium 22 beyond the edges of the window24. The orientation of the filter medium 22 is such that the filtermembrane/waterproof layer is facing outwards (away from the viewer inthis figure) and the support layer which provides mechanical strength,forms the facing layer for welding to the coated side of the pillowcover.

This arrangement solves both of the mechanical failure problems byremoving the filter medium 22 from the seam area, to an area where nopeel forces are experienced, and by maintaining the correct orientationof surface contact between media for welding.

With the filter medium of the present invention, the filter membraneprovides the liquid resistance, but allows for air permeability due tothe construction of the PVC backing The addition behind the filtermembrane of the strengthening layer, preferably manufactured of a spunnon-woven polypropylene (PP) material (alternatively, other syntheticmaterials could be used for this purpose), provides the additionalstrength required around the welded join of the filter medium to thewindow/strip provided in the pillow cover for the application of thefilter. This is achieved because of the strengthening layer being formedof meltable material (i.e. the non-woven PP) being melted into the PUcoating of the pillow cover fabric as well as into the filter membrane,thereby providing a stronger welded seam to prevent the risk of theinfection control product bursting.

In addition, the window/strip is designed so that the seams (joiningedges) of the filter medium/window are not integrated with the mainperimeter welded seam of the pillow where it would weaken the overallstrength of the seam. Therefore, the window has been re-designed in suchaway that its edges or “frame” is separate and distinct from the edgesof the pillow cover allowing for the strong weld of the medium/windowdescribed whilst maintaining the integrity of the main welded seam ofthe pillow.

In the second embodiment which is shown in and described with referenceto FIGS. 2 and 3, only one vent is provided on the pillow 20. However,it will be understood that any number of vents may be provided asrequired, each with an appropriate bacteriological filter mediumassociated therewith.

Referring now to FIGS. 4, 5, 6 and 7, a third embodiment of theinfection control bedding product will now be described. In the drawingsof the product in the third embodiment, like numerals refer to likefeatures shown of the first and second embodiment.

Referring initially to the FIGS. 4, 5, 6 and 7, the infection controlpillow in the third embodiment is indicated generally by referencenumeral 30 and the pillow 30 includes a vent indicated generally by thereference numeral 32. The infection control pillow 30 includes a pillowcover 31, a vent 32 comprising a polyurethane (PU) gasket 36,spun-bonded polypropylene strengthening layer 35 and filter membrane(also referred to hereinbelow as a medical membrane) 33. After each ofthese components has been affixed together preferably by welding, eachof these layers will be compressed together to form the infectioncontrol product of the present invention.

Components of the Infection Control Pillow Product in the Most PreferredEmbodiment

-   Main Pillow Cover 31 manufactured of polyurethane (PU) coated    polyamide—(preferably, Redwood ‘ICE’ Fabric)-   Medical membrane 33 such as medical membrane MMT-302 produced by    W.L. Gore & Associates, Inc., 401 Airport Road, Elkton, Md., United    States of America.-   Spun-bonded Polypropylene membrane 35.-   PU gasket 36.

Details of Each Component

Pillow Cover 31:

The pillow cover 31 is manufactured of 135 g/m² polyurethane (PU) CoatedPolyamide.

The PU coating provides protection against fungi and bacteria.

The infection control product including the vent is washable at 75° C.The infection control product is gentle to the skin and also has theadvantage that the inclusion of the vent in the product does not createnoise which is, of course, undesirable in particular when the product isused in a hospital environment by a patient.

Filter Membrane (Medical Membrane):

The filter membrane 33 is a breathable membrane which allows air to beexpelled from within the pillow when compressed thereby preventing theunwanted effect of ‘ballooning’ around the patients head/mouth.

The breathable medical membrane 33 also protects the structure(including the RF welded seams) of the infection control product,ensuring the seams are not overstressed when the pillow is compressed,basically preventing a rupture should the entire pillow be compressed.

The medical membrane 33 has been tested vigorously as a microbialbarrier and performed extremely well.

Spun-Bonded Polypropylene Layer 35:

The periphery shape and dimensions equal to medical membrane 33.

The purpose of including the spun-bonded polypropylene is to add greaterstrength to the vent area. The spun-bonded polypropylene layer 35 isinserted behind the medical membrane 33 and it prevents simple puncturesfrom hands/fingers.

Polyurethane (PU) Gasket 36:

The polyurethane gasket is slightly smaller than the rectangular RF weldarea, yet slightly larger than the medical membrane and spun-bondedpolypropylene. This ensures that the edge of medical membrane andspun-bonded polypropylene are completely sealed down to the pillow coversurface. Thus the edges of each of the layers are sealed and compressed,thereby resulting in a completely smooth, patient friendly, surface.

The purpose of the PU gasket 36 is to add more plastic to the weld area,allowing more plastic to flow into the Spun-bonded polypropylene layer,the medical membrane 33 and the PU coated pillow cover, increasing thequality/strength of the bond of the various layers.

Welds:

1. Long Welds Along the Pillow Cover Edges

The long welds along the edges of the pillow cover are fully RF welded.This gives a seam which is completely impermeable to liquid.

2. Closing Weld to Complete Filled Pillow

Whether RF welded or heat sealed closed, the closing weld encapsulatesthe pillow filler and completes the impermeable peripheral seam.

Fire Testing:

A complete pillow produced in accordance with the process of theinvention, filled and sealed, has undergone fire testing. The completepillow performed extremely well in the fire tests, scoring an FR ratingof Crib 5.

Referring now to FIG. 8, the components of the vent 32 are shown stackedon top of the welding tool. The welding tool has a larger surface thanthe components, so as to ensure that the edge around the perimeter ofthe vent 32 and the aperture 38 is completely sealed.

Referring now to FIG. 9, a finished weld is shown, a glossy bead of PUis provided around the perimeter of the membrane 33 and spun-bondedpolypropylene 35. The PU ensures the edge is sealed and impermeable.

The method of manufacture of the hermetically sealed infection beddingproduct such as a cushion, pillow, duvet, mattress or such like, inaccordance with the invention comprises the steps of:

-   -   a) providing a filter membrane,    -   b) providing a strengthening layer,    -   c) providing a gasket,    -   d) providing a cover of the bedding product, the cover having an        aperture;    -   e) locating the PU gasket, the strengthening layer and the        filter membrane in the aperture,    -   f) affixing the layers a), b), c) and the cover of the product        together so that the layers are sealed together and are        impermeable to liquid, whereby the filter membrane,        strengthening material and the gasket are bonded together with        the cover of the infection control bedding product, at the        aperture in the cover so as to provide a vent in the infection        control bedding product.

The layers of the filter medium 32 are bonded together by glueing orwelding such as heat welding, ultrasonic welding, compression welding orRF welding. Preferably, the bonding is carried out by RF welding withthe RF welding apparatus operating in a range of 27.12 MHz±160Kilohertz.

In order to produce the infection control pillow 30, a welding apparatusis used in which the welding action required is performed effectively.The method for producing the infection control product 30 as describedabove ensures that the product 30 can be replicated and mass produced.

Thus, the present invention provides a pillow or the like which isparticularly advantageous for use in hospitals and other medicalinstitutions as a safeguard against the spread of bacteria and HospitalAcquired Infection (HAI), in general. The present invention can also beapplied to other bedding products such as mattresses, cushions includingwheelchair cushions and duvets, for example, which similarly have asealed cover containing resiliently deformable filling material.

It will be appreciated that though the invention has been described withreference to a hermetically sealed pillow, the invention provides forinfection control for bedding and soft furnishings generally. Indeed,advantageously, the invention can be applied in any situation wherethere is a regular change-over in persons using pillows, duvets and thelike to prevent cross-infection. In addition to high risk areas such ashospitals and medical institutions generally, the invention can beapplied more widely in other situations where there is a regularturnover of persons using this type of bedding and furnishings, such asin hotels, guesthouses and the like. The infection control pillow andbedding products of the invention may also be used in domesticapplications to avoid problems with dust mites and fungal infections. Itis also envisaged that this type of pillow product could be incorporatedin headrests for airline seating, as well as having militaryapplications including sleeping bags and the like.

It is to be understood that the invention is not limited to the specificdetails described here which are given by way of example only and thatvarious modification and alterations are possible without departing fromthe scope of the invention as defined in the appended claims.

We claim:
 1. An infection control bedding product comprising: a fillingmaterial; a cover enclosing the filling material, the cover including anaperture configured to vent the infection control bedding product; afilter membrane; a strengthening layer attached to the filter membrane;a gasket attached to the strengthening layer; the gasket extending pastthe perimeter of the aperture and attached to the cover; the infectioncontrol product being a substantially liquid impermeable air permeablemicrobial barrier.
 2. An infection control bedding product as in claim1, wherein the strengthening layer is disposed intermediate the filtermembrane and the gasket.
 3. An infection control bedding product as inclaim 1, wherein the filter membrane, the strengthening layer, thegasket and the cover are bonded together to form a liquid impermeableseal.
 4. An infection control bedding product as in claim 1, wherein thefilter membrane has a pore size between about 2 and 4 microns, and thefilter membrane and the strengthening layer have: air flow between about20 and 40 liters per minute per square centimeter at 1 bar differentialpressure, and resistance to water of between about 0.2-0.8 bar entrypressure.
 5. An infection control bedding product as in claim 1, whereinthe gasket and the cover comprise a first material.
 6. An infectioncontrol bedding product as in claim 5, wherein the first materialcomprises polyurethane.
 7. An infection control bedding product as inclaim 1, wherein the filter membrane comprises an oleophobic expandedpolytetrafluoroethylene (PTFE) membrane.
 8. An infection control beddingproduct as in claim 1, wherein the gasket and the cover are bonded toform a vent seam, the infection control bedding product includes aperimeter seam, and the vent seam is not integral with the perimeterseam.
 9. An infection control bedding product comprising: a fillingmaterial; a cover enclosing the filling material, the cover including anaperture configured to vent the infection control bedding product and aliquid impermeable polyurethane coating; a substantially liquidimpermeable air permeable microbial barrier filter membrane; astrengthening layer attached to the filter membrane and extending pastthe perimeter of the aperture, the strengthening layer bonded to thecover; and the infection control product being a liquid impermeable airpermeable microbial barrier.
 10. An infection control bedding product asin claim 9, further comprising a gasket, wherein the strengthening layeris disposed intermediate the filter membrane and the gasket.
 11. Aninfection control bedding product as in claim 9, wherein the filtermembrane, the strengthening layer, and the cover are bonded together toform a liquid impermeable seal.
 12. An infection control bedding productas in claim 9, wherein the filter membrane has a pore size between about2 and 4 microns, and the filter membrane and the strengthening layerhave: air flow between about 20 and 40 liters per minute per squarecentimeter at 1 bar differential pressure, and resistance to water ofbetween about 0.2-0.8 bar entry pressure.
 13. An infection controlbedding product as in claim 9, wherein the filter membrane comprises anoleophobic expanded polytetrafluoroethylene (PTFE) membrane.
 14. Aninfection control bedding product as in claim 9, wherein thestrengthening layer and the cover are bonded to form a vent seam, theinfection control bedding product includes a perimeter seam, and thevent seam is not integral with the perimeter seam.
 15. An infectioncontrol bedding product comprising: a filling material; a coverenclosing the filling material and having an aperture, the covercomprising a liquid impermeable material; a liquid impermeable airpermeable microbial barrier vent comprising: an oleophobic expandedpolytetrafluoroethylene (PTFE) membrane extending past the perimeter ofthe aperture; and a nonwoven layer extending past the perimeter of theaperture; and a gasket bonded to the PTFE membrane, the nonwoven layerand the cover to form a liquid impermeable seal rendering the infectioncontrol bedding product liquid impermeable.
 16. An infection controlbedding product as in claim 15, wherein the nonwoven layer comprises atleast one of a polyvinyl chloride (PVC) nonwoven material and apolypropylene nonwoven material.
 17. An infection control beddingproduct as in claim 16, wherein the polypropylene nonwoven materialcomprises a spun fibre polypropylene material.
 18. An infection controlbedding product as in claim 15, wherein the nonwoven layer comprises asupport backing nonwoven fused or laminated to the PTFE membrane and astrengthening nonwoven material.
 19. An infection control beddingproduct as in claim 15, wherein the vent has air flow between about 20and 40 liters per minute per square centimeter at 1 bar differentialpressure, and resistance to water of between about 0.2-0.8 bar entrypressure.
 20. An infection control bedding product as in claim 15,wherein the cover and the gasket comprise a polyurethane material.